Sunday, March 30, 2014

Rainwater Harvesting Expert Brad Lancaster to Speak in Las Cruces


We drink it. We need it. We eat plants and animals that can't live without it. And we know potable water is scarce and will soon be scarcer.

Almost every previous civilization faced with drought has practiced some form of rainwater harvesting. Ours really hasn't.

On April 10th , Brad Lancaster will visit Las Cruces. Mr. Lancaster has studied the world's water-harvesting practices and experimented extensively with them. His desert home resembles, in Gary Nabhan's words, “a walk-through encyclopedia” of the world's water-harvesting methods. He's advised Tucson and other municipalities how to apply some of these methods.

His talk here will be free, thanks to the Doña Ana County Master Gardeners and the Las Cruces City Council. He speaks at 7 p.m. on Thursday, April 10th at the Rio Grande Theater. (Doors open at 6:30. Mr. Lancaster will mingle with guests until his presentation, then stay to answer questions and sell books afterward.)

Water is way too important to leave to politicians and corporations. We should each learn what we can about harvesting it, using it, and conserving it. Many of the methods that Lancaster will discuss (and explains in more detail in his books) we could each employ, without a big budget or extensive technical knowledge. Others, such as greywater and stormwater harvesting, we should demand our city or county employ.

The key is to gather as much as possible of the rainwater we do get, so as to use it as long as possible.

That may sound goofy in Las Cruces, where rain's a rarity.

But Tucson's pretty similar, with annual rainfall under 12 inches.

Twenty years ago Brad and his brother began to harvest rain from the roof of their home on 1/8th of an acre in Tucson. They now harvest rainwater on that urban lot and an adjoining right-of-way.

How much fresh water can you acquire that way? Couldn't be much. But wait: would you believe 100,000 gallons annually?

According to the USGS website, the average person uses 80-100 gallons per day – 29,200 to 36,500 gallons per year.

Brad's 100,000 gallons is enough for three people, including water for their shade trees. One Saturday they illegally cut through a small concrete curb protecting their land from water running down the street. They let the water in. They shaped the land to hold it there. They shared this secret with the whole neighborhood, Dunbar Springs. Now Dunbar Springs harvests two acre feet of water a year – enough to cover two acres with water a foot high.

Diverting the water helps increase the density of trees, and thus the availability of shade (and fruit from the trees). Trees help increase rainfall. Diminishing the amount of water on the roads reduces potholes.

Rainwater's not only free, it's far better for plants than groundwater, which grows increasingly salty and brackish as we drill more and more deeply into our underground supply.

We require just a small mental adjustment: instead of engineering ways to get water to flow away, let some of it stay and make itself useful. As Lancaster says, “It's insane that we're spending all these resources bringing inferior water to this place when we have a much higher quality, salt-free water falling from the sky.”

This ain't a Progressive Voters' Alliance vs. the Tea Party issue. Thinking folks of all political complexion should agree. Doesn't matter whether you're harvesting rainwater because it saves on your water bill, because you don't like paying the government for water, because you figure climate change will deepen the drought, or because you want to treat your vegetables and trees to better-quality water. It's just common sense.

In 1995, soon after Brad started harvesting, he traveled through southern Zimbabwe. Hearing of a man who farmed water, he went to the country's driest region. He found the water farmer in a very simple office, reading a Bible.

Zephaniah Phiri took Brad to his farm. He had been fired from his railway job in 1964, for political activity against Rhodesia's white-minority government. They said he'd never work again. To support his family of eight, he turned to his overgrazed and eroding seven-acres – and to the Bible. Inspired to create a Garden of Eden, but lacking the Tigris and Euphrates Rivers, he set out to recreate their abundance from storm runoff.

Over a 30-year period, he created a sustainable system in which rainwater now provides all his water needs. His 7.4 acre farm provides abundant food and fruit.

One chapter in Rainwater Harvesting for Drylands and Beyond describes Mr. Phiri's work (and, with practical tips and diagrams, the eight principles applicable to all water-harvesting sites). Mr. Phiri says, of land like ours where rain falls fast and leaves fast, “When there are thunderstorms, soil and water try to elope together and run away from my land. It is my job to persuade them to settle down here and raise a family.”

If his books are any indication, Brad's talk should be lively, practical, and interesting.

[The column above appeared this morning, Sunday, 30 March, in the Las Cruces Sun-News.  Again, the talk is at 7 p.m. Thursday April 10, at the Rio Grande Theater.  Doors open at 6:30, and Brad will mingle with early arrivals.  He'll also answer questions afterward, sell books, sign books, and chat.]

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